Acute kidney injury in dogs following ingestion of cream of tartar and tamarinds and the connection to tartaric acid as the proposed toxic principle in grapes and raisins

Dear Editor, We are very interested in the report of cases of tartaric acid and tartrate poisoning from tamarinds and cream of tartar contributed by Wegenast and colleagues,1 which support the theory that this is the cause of acute kidney injury (AKI) associated with grape and raisin poisoning. We would like to contribute additional supporting data. At the Veterinary Poisons Information Service (VPIS), UK, we have no reported cases involving tamarind but do have cases involving cream of tartar. One dog, an adult Labrador, developed vomiting, inappetence, and AKI after ingestion of an unknown amount of cream of tartar. The dog was euthanized, and results of a urine sample received after euthanasia was positive for Haemophilus haemoglobinophilus, which may have been a confounder. Although dogs appear to be particularly susceptible to AKI from tartrates and tartaric acid,1 cases have also been reported in people, although 10–20 g of sodium tartrate was used previously as a laxative in people. Acute tubular necrosis has been reported after ingestion of tartaric acid2 and fatal tubular nephropathy occurred in an adult male following accidental ingestion of 30 g of tartaric acid.3 Wegenast and colleagues mention that tartaric acid delays gastric emptying, which may explain prolonged retention of dried vine fruits in the stomach. In addition, raisins are hygroscopic and can double or triple in volume on contact with water, and phytobezoars involving raisins have been reported in people.4, 5 Wegenast and colleagues suggest that cooked grapes and raisins are less likely to be implicated in cases of AKI due to thermal decomposition of tartaric acid. In a study comparing thermal decomposition of pure tartaric acid and that in waste samples from the grape juice and wine industries, the peak decomposition of pure tartaric acid occurred at 208°C but was closer to 300°C for the waste products.6 We have fatal cases of AKI in dogs after ingestion of Christmas pudding and fruit cake (including Christmas cake), all of which are rich in dried vine fruits. These baked goods are cooked for a prolonged period, but at a relatively low temperature (usually around 120–140°C), so it is difficult to know if the poor outcome was due to the dose ingested or the low cooking temperature resulting in incomplete decomposition of tartaric acid. Late presentation was a characteristic of these cases and is well recognized as a factor contributing to poor outcome in cases of tartaric acid-containing foods. Interestingly, we have no fatal cases involving other baked goods containing dried vine fruits such as scones or mince pies that are typically cooked for a shorter time at higher temperatures, but generally not above 200°C. We still have a great deal to learn about grape and raisin toxicosis in dogs, but the recognition of tartaric acid as the probable causative agent is a breakthrough. Our data support the findings of Wegenast and colleagues, but data are still lacking, and current treatment advice remains unchanged. Now we need to understand the effect of cooking on vine fruits and other factors that influence the outcome in dogs that ingest tartaric acid-containing foods. We would welcome further well-described case reports, particularly with information on doses ingested. Respectfully,

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.